The requirements you list are incredibly broad and there is so much to choose from. Something like the A900x is undoubtedly a safe and smart choice. And if you just want an incredibly durable workhorse headphone that is an efficient great sounding all rounder (other than the A900x) there are...

Some Beyerdynamic DT75s I bought at a music shop. Not sure what happened to them actually.

LOL Straight to the defensive. Whatever man, I don't come here to validate your choices.

The Shures are certainly great. But OP specifically wanted Beats like bass, so my recommendation would be ATH-M50. Seriously, the M50 is one the best bang for buck headphones there is and ideal for your purposes. You won't need an amp either. V-Modas aren't bad, but I've listened to the...

HM3s are circumnaural if that's what you mean. :)

Brainwavz HM3... Not sure about ebay, but they are $50 on amazon. http://www.amazon.com/Brainwavz-HM3-BRAINWAVZ-On-Ear-Headphones/dp/B0067GNWB0

Why not go a Schiit Lyr? Power to spare and designed with orthos in mind... Combine with a Bifrost for (mainly aesthetic) synergy... or just take your pick of any DAC.

LOL

You basically described my exact experience of what my K702 sounded like when not amped adequately, i.e. straight out of my STX. Volume was fine, but didn't sound right: harsh top end, gurgly and distant vocals, flat and lifeless. I think it is partly due to the K702 revealing the lower quality...

The worst I've heard (that cost any sort of money, so airplane buds aside) were a pair of those House of Marley ones. Just a dreadful flat, muddy sound and like $200.

Haven't heard the HE-400, but I have heard other Hifiman orthos (HE-6 and HE-500) and I did like them a lot. Very smooth sound. Only I'd still much prefer Grados for rock. Especially hard rock/grunge/metal where I like headphones with a little more attack. Have you heard the RS2i?

I'd probably go the Grados.

Sounds like the D1 is probably a pretty good solution for you. As for the mic, you'll have to go in via the computer soundcard, or alternatively buy a usb mic.

Even there, it's not really an advantage unless you want to play 192/24 files... And to be honest, even on higher end stuff the difference between 96/24 and 192/24 is barely (if at all) audible. I've had a couple of Fiios and I don't think they are anywhere near good enough to warrant such...

Yeah the DT250 is probably the ideal replacement here and definitely meets all criteria. Also probably the only headphone mentioned so far that is actually sonically superior to the Shures. You could look for a used DT250. I got mine for like $140 and its a tank.

My problem is I'm a fan of Grado, Beyerdynamic, AKG and Audio Technica.

I reckon you should just get them fixed. SRH840s are pretty damn good headphones for the money, I doubt you'd find better under $100.

I gotta agree with the turtle, tubes aren't "the best", they are just different. Most (I didn't say all) of the best amps south of $1k are going to be solid state anyway. The only tube amps you'll get within that budget and still have nice headphones are cheap and nasty Chinese ones, which are...

AD900 and AD700 are probably the most comfortable headphones I've worn. Not sure if the AD700 fits your taste, but it can be got for well under $200.

I actually quite like the T70. I agree that it definitely doesn't have the same high end sparkle as ATs do though. Both the T70 and T70p are easy to drive. The T70 will sound better with an good amp, but I've run mine out of both a phone and a Fiio e10 with acceptable results (the problem was...

Go with the M50... It used to cost $200+ and was decent value then, now it's just insanely good value.

I'd forget the HD598 if you want isolation. The M50 is a great choice. I also like the Shure SRH840, which similar price/size but a little more neutral sounding than the M50.

I agree with Doc. Probably can't go wrong with either. It's down to taste. From my memory, the M50 had that typical Audio Technica sparkly top-end but plenty of bass. The DT770 was similar but less so, sounded more like a Beyerdynamic... That's probably not helpful... But both are on the bassier...